A somewhat obscure anniversary for the 15th is the first electrical welding during an EVA, according to Roskosmos:

Electrical welding was first performed in space 25 years ago by Svetlana Savitskaya and Vladimir Dzhanibekov, Russian cosmonauts. They spent 3.5 hours in outer space cutting and welding pieces of metal. The universal space welding machine was designed by Electrical Welding Institute, Kiev. For more than 10 years, the scinetists were developing this complicated instrument.

Today the cosmonauts involved in this first space welding attempt tell about their experience.

"It was easy due to 0-gravity", says Svetlana Saviskaya. "However, many people thought that we had made a special performance, that we hadn`t been working in space. Like with the first step on the Moon".

"In outer space, with this invisible ray, it was a real miracle", adds VLadimir Dzhanibekov.

The machine was tested deeply, but the developers could not define its behaviour in space precisely.

Specialists of the Kiev institute are still sure that their instrument will be used in future. The first welding in space opened one more page in the space exploration history.

Today Russian cosmonauts and scientists from Kiev recollect their past achievements and the time when Russia and Ukraine were conquering space together...

Also a photo of Svetlana welding, probably the only photo of a female cosmonaut doing an EVA? (From the Capcomespace site)

Thanks for bringing this to the awareness of those who did not know of this event. I cannot imagine welding in space, it is quite an accomplishment that seems to have gone by unnoticed.

Apart from several questions regarding how melted metal acts in zero gravity, how did they suppress those sudden slag eruptions that would burn a hole right through a spacesuit in a flash? (I know they burn a hole right through my scalp!) What metals did they weld? Did they use some type of metal or tungsten inert gas shielding system?

Thanks for bringing this to the awareness of those who did not know of this event. I cannot imagine welding in space, it is quite an accomplishment that seems to have gone by unnoticed.

Apart from several questions regarding how melted metal acts in zero gravity, how did they suppress those sudden slag eruptions that would burn a hole right through a spacesuit in a flash? (I know they burn a hole right through my scalp!) What metals did they weld? Did they use some type of metal or tungsten inert gas shielding system?

By the way, 1st welding experiment in space was undertaken in 1969 aboard Soyuz-6, but that was inside the pressurized volume, not in vacuum. The cosmonauts nearly burned a hole through their orbital module's hull then.

By the way, 1st welding experiment in space was undertaken in 1969 aboard Soyuz-6, but that was inside the pressurized volume, not in vacuum. The cosmonauts nearly burned a hole through their orbital module's hull then.

How long it took to cool the joint enough for it to "solidify" in a no atmosphere environment was another of the points that had me curious, as that has a direct result on the properties of the weld joint (granulation, tempering, normalizing, etcetera).